Preload by axial displacement

For machining centres, milling machines, lathes, and drills, rigidity and precise axial guidance are critical parameters, especially when alternating axial loads occur. For these applications, the preload in the bearings is usually obtained by adjusting the bearing rings relative to each other in the axial direction.

This preload method offers significant advantages in terms of system rigidity. However, depending on the bearing internal design and ball material, preload increases considerably with rotational speed as a result of centrifugal forces.

Universally matchable bearings or matched bearing sets are manufactured so that when mounted properly, they attain their predetermined axial displacement and proper preload values (fig. 1).